Screw driver system

ABSTRACT

A screw driver system includes a screw driving bit and a guide clamp. The screw driving bit includes a unitary body having a first end and a second end with a longitudinal axis defined therebetween and an outer surface having a cylindrical portion between the first and second ends. The screw driving bit includes a first circumferential groove and a second circumferential groove that are affixed in coaxially positioned arrangement about the longitudinal axis on the outer surface of the cylindrical portion each having a bottom surface. The bottom surface of the first circumferential groove defines a first outer diameter that is larger than a second outer diameter defined by the second circumferential groove. The guide clamp includes a jaw for holding the screw driving bit. When engaged with the first circumferential groove, the guide clamp prevents rotation of the screw driving bit. When engaged with the second circumferential groove, the guide clamp does not prevent rotation of the screw driving bit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/982,270, filed on May 17, 2018, the entire contents of which areincorporated herein by reference.

FIELD

The application relates to screw driver systems for use in surgicalprocedures.

BACKGROUND

Hip implant devices are a common means of replacing degenerated joints.Such implant devices often include a cup to replace or supplement theacetabulum. Often the acetabular cup includes a shell that is fixedlycoupled to the patient's anatomy and a liner that fits within the shelland provides a smooth, resilient surface for contact with the head of afemoral implant. The shell can be fixed to the patient's anatomy using avariety of means, including screws. A variety of tools can be used toinstall and/or remove the screws into the cup including various screwdrivers or wrenches.

SUMMARY

In one embodiment, a screw driving bit is disclosed that includes abody, a shaft engaging portion, a screw engaging portion, a firstcircumferential groove, and a second circumferential groove. The bodyhas a first end and a second end and defines a longitudinal axis betweenthe first end and the second end. The body has an outer surface with acylindrical portion between the first end and the second end. The shaftengaging portion is at the first end and is configured to couple to ashaft. The screw engaging portion is at the second end and is shaped andconfigured to engage a head of a screw. The first circumferential grooveand second circumferential groove are provided on the outer surface ofthe cylindrical portion. Each of the circumferential grooves has sidewalls and a bottom surface. The bottom surface of the firstcircumferential groove defines a first outer diameter and the bottomsurface of the second circumferential groove defines a second outerdiameter. The second circumferential groove is deeper than the firstcircumferential groove, whereby the second outer diameter is smallerthan the first outer diameter. The first circumferential grooveaccommodates a guide clamp for tightly holding the screw driving bit byclamping the first circumferential groove's bottom surface. In addition,the second circumferential groove accommodates the guide clamp forrotatably holding the screw driving bit by engaging the secondcircumferential groove without clamping the second circumferentialgroove's bottom surface.

In another embodiment, a screw driver is disclosed that includes a shaftand a screw driving bit. The shaft is configured for manipulation by auser. The driving bit is configured to couple to the shaft. The drivingbit includes a body, a shaft engaging portion, a screw engaging portion,a first circumferential groove and a second circumferential groove. Thebody has a first end and a second end and a longitudinal axis definedbetween the first end and the second end. The body has an outer surfacewith a cylindrical portion between the first end and the second end. Theshaft engaging portion is at the first end and is configured to coupleto the shaft. The screw engaging portion is at the second end and isshaped and configured to engage a head of a screw. The firstcircumferential groove and second circumferential groove are provided onthe outer surface of the cylindrical portion. Each of thecircumferential grooves has side walls and a bottom surface. The bottomsurface of the first circumferential groove defines a first outerdiameter and the bottom surface of the second circumferential groovedefines a second outer diameter. The second circumferential groove isdeeper than the first circumferential groove, whereby the second outerdiameter is smaller than the first outer diameter. The firstcircumferential groove accommodates a guide clamp for tightly holdingthe screw driving bit by clamping the first circumferential groove'sbottom surface. In addition, the second circumferential grooveaccommodates the guide clamp for rotatably holding the screw driving bitby engaging the second circumferential groove without clamping thesecond circumferential groove's bottom surface.

In another embodiment described herein, a screw driver system includesthe screw driver and the guide clamp. The guide clamp includes anelongated shaft and a closable jaw. The closable jaw is configured forholding the screw driving bit. The jaw maintains an opening when closed,wherein the opening has a diameter that is larger than the second outerdiameter of the screw driving bit but smaller than the first outerdiameter of the screw driving bit. The guide clamp can tightly hold thescrew driving bit by engaging the closable jaw into the firstcircumferential groove and clamping the first circumferential groove'sbottom surface and restricting the screw driving bit from rotating aboutits longitudinal axis. The guide clamp can rotatably hold the screwdriving bit by engaging the closable jaw into the second circumferentialgroove without clamping the second circumferential groove's bottomsurface, thus allowing the screw driving bit to rotate about itslongitudinal axis while being held by the guide clamp.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the screw driver systemsdescribed herein will be more fully disclosed in, or rendered obviousby, the following detailed description of the preferred embodiments,which is to be considered together with the accompanying drawingswherein like numbers refer to like parts and further wherein:

FIG. 1 shows a perspective view of a screw driver having an elongatedshaft and a driving bit.

FIG. 2 shows a perspective view of a driving bit according to anembodiment of the present disclosure.

FIG. 3A shows a side view of the driving bit of FIG. 2.

FIG. 3B shows a second side view of the driving bit of FIG. 2.

FIG. 3C shows a side view of a driving bit according to anotherembodiment of the present disclosure.

FIG. 4A shows a perspective view of a guide clamp in a closedconfiguration.

FIG. 4B shows a perspective view of the guide clamp in an openconfiguration.

FIG. 5 shows a longitudinal cross-section view of the screw driversystem of FIG. 1 in a first configuration in which a guide clamp isengaged with a first circumferential groove of the driving bit.

FIG. 6 shows a longitudinal cross-section view of the screw driversystem of FIG. 1 in a second configuration in which the guide clamp isengaged with a second circumferential groove of the driving bit.

FIG. 7 shows a perspective view of the screw driver system of FIG. 1engaged with a screw in an acetabular cup.

FIG. 8 shows a perspective view of a driving bit according to anotherembodiment of the present disclosure.

DETAILED DESCRIPTION

This description of preferred embodiments is intended to be read inconnection with the accompanying drawings, which are to be consideredpart of the entire written description of this invention. The drawingfigures are not necessarily to scale and certain features of theinvention may be shown exaggerated in scale or in somewhat schematicform in the interest of clarity and conciseness. In the description,relative terms such as “horizontal,” “vertical,” “up,” “down,” “top,”and “bottom” as well as derivatives thereof (e.g., “horizontally,”“downwardly,” “upwardly,” etc.) should be construed to refer to theorientation as then described or as shown in the drawing figure underdiscussion. These relative terms are for convenience of description andnormally are not intended to require a particular orientation. Termsincluding “inwardly” versus “outwardly,” “longitudinal” versus “lateral”and the like are to be interpreted relative to one another or relativeto an axis of elongation, or an axis or center of rotation, asappropriate. Terms concerning attachments, coupling and the like, suchas “connected” and “interconnected,” refer to a relationship whereinstructures are secured or attached to one another either directly orindirectly through intervening structures, as well as both movable orrigid attachments or relationships, unless expressly describedotherwise. The term “operatively or operably connected” is such anattachment, coupling or connection that allows the pertinent structuresto operate as intended by virtue of that relationship. In the claims,means-plus-function clauses, if used, are intended to cover thestructures described, suggested, or rendered obvious by the writtendescription or drawings for performing the recited function, includingnot only structural equivalents but also equivalent structures.

The present disclosure describes a screw driver system that simplifiesthe installation and/or removal of screws. Specifically, the screwdriver systems described herein allow a surgeon or other operator tocontrol a screw driving bit while installing or removing screws in anacetabular cup. Because of space constraints, when performing a hipreplacement surgery, the surgeon is typically unable to manipulate thescrew driving bit directly with her hand. As a result, the screw drivingbit can disengage from the head of the screw. The screw driver systemsdescribed herein provide grooves that the surgeon can engage with aguide clamp to control and maneuver the screw driving bit duringinstallation or removal of the screws. This greatly simplifies theinstallation or removal process.

FIG. 1 shows a screw driver 12 comprising an elongated shaft 16 and ascrew driving bit 18 according to one embodiment The elongated shaft 16can be connected to a handle that is configured for manipulation by auser, such as a surgeon. In one embodiment, a universal joint 39connects the screw driving bit 18 to the shaft 16. The universal joint39 allows the shaft 16 and the screw driving bit 18 to articulaterelative to one another to provide easier positioning of the driving bit18 in a desired position.

As shown in FIGS. 2 and 3A, the screw driving bit 18 includes a body 20,a shaft engaging portion 22, a screw engaging portion 24, a firstcircumferential groove 26, and a second circumferential groove 28. Thebody 20 has a first end 30 and a second end 32 and defines alongitudinal axis A (shown in FIG. 3A) between the first end 30 and thesecond end 32. The body 20 has an outer surface 34 comprising acylindrical portion 36 between the first end 30 and the second end 32.

Referring to FIG. 3A, the shaft engaging portion 22 is disposed at thefirst end 30 and is configured to couple the driving bit 18 to the shaft16. The shaft engaging portion 22 can couple the driving bit 18 to theshaft 16 in any appropriate manner. For example, in one embodiment, asshown in FIG. 1, a universal joint 39 couples the shaft 16 and thedriving bit 18. In one such embodiment, as shown in FIGS. 2, 3A, and 3B,the shaft engaging portion 22 is a u-shaped extension that forms aportion of the universal joint 39.

In another embodiment, as shown in FIG. 3C, the shaft engaging portion22 forms an extension which is inserted into a recess in the universaljoint 39. In an alternative embodiment, the shaft engaging portion 22 ofthe driving bit 18 includes a recess 25 configured to receive anextension of the universal joint 39, similar to a socket wrench. Thedriving bit 18 is, thereby, removably coupled to the shaft 16. Inanother alternative embodiment, the driving bit 18 is fixedly coupled tothe shaft 16. For example, the driving bit 18 can be integrally formedwith the universal joint 39.

The screw engaging portion 24 of the screw driving bit 18 is configuredto engage a head of a screw. For example, as shown in FIGS. 2 and 3A,the screw engaging portion 24 can be in the form of a male headconfigured to engage a recess formed in the head of the screw. Forexample, the male head can have a hexagonal cross-section, similar to anAllen wrench, and be configured to mate with a hex socket of the head ofthe screw. The male head can also be in the form of a Torx head, a Torxplus head, a Phillips head, a bladed head, a Pozidriv head, a Supadrivhead, a square head, or any other appropriate configuration.Alternatively, the screw engaging portion 24 can be in the form of afemale head configured to engage a male head of the screw. The femalehead, for example, can be in the form of a hex socket.

The first circumferential groove 26 has side walls 26 a and a bottomsurface 26 b. The side walls 26 a can be oriented orthogonal to thelongitudinal axis A such that the first circumferential groove 26 has arectangular cross-section. Alternatively, the side walls 26 a can beoriented at an oblique angle with respect to the longitudinal axis A.Orienting the side walls 26 a at an oblique angle can allow a “lead-in”to the first circumferential groove 26 and allow easier engagement withthe guide clamp 14. The bottom surface 26 b of the first circumferentialgroove 26 defines a first outer diameter 27 (shown in FIG. 3B).

The second circumferential groove 28 has side walls 28 a and a bottomsurface 28 b. The side walls 26 a can be oriented orthogonal to thelongitudinal axis A such that the second circumferential groove 28 has arectangular cross-section. Alternatively, the side walls 28 a can beoriented at an oblique angle with respect to the longitudinal axis A.Orienting the side walls 28 a at an oblique angle can allow a “lead-in”to the second circumferential groove 28 and allow easier engagement withthe guide clamp 14. The bottom surface 28 b of the secondcircumferential groove 28 defines a second outer diameter 29 (shown inFIG. 3B).

As shown best in FIG. 3B, the second circumferential groove 28 is deeperthan the first circumferential groove 26 such that the second outerdiameter 29 is smaller than the first outer diameter 27. This allows theguide clamp 14 to restrict rotation of the driving bit 18 when engagedwith the first circumferential groove 26 and allow rotation of thedriving bit 18 when engaged with the second circumferential groove 28,as will be described in more detail herein.

The first circumferential groove 26 and the second circumferentialgroove 28 are offset from one another along the longitudinal axis A. Inone embodiment, as shown in FIGS. 2, 3A, and 3B, the firstcircumferential groove 26 is distally disposed (i.e., closer to thescrew engaging portion 24) relative to the second circumferential groove28. Alternatively, in other embodiments, the first circumferentialgroove 26 is distally disposed (i.e., closer to the shaft engagingportion 22) relative to the second circumferential groove 28.

In one embodiment, the first circumferential groove 26 and the secondcircumferential groove 28 circumscribe the entire circumference of thedriving bit 18. In another embodiment, one or both of the grooves 26, 28only circumscribe a portion of the driving bit 18. In one embodiment,the first circumferential groove 26 is a partial groove such that theguide clamp 14 can only engage and disengage the first circumferentialgroove 26 in certain orientations.

As shown in FIGS. 4A and 4B, the guide clamp 14 includes arms 41 and aclosable jaw 42. The closable jaw 42 forms an opening 44 when closed(shown in FIG. 4A), the opening 44 having a diameter that is smallerthan the first outer diameter 27. As a result, the guide clamp 14 cantightly hold the driving bit 18 by engaging the closable jaw 42 into thefirst circumferential groove 26 and clamping the bottom surface 26 b ofthe first circumferential groove 26. When engaged with the firstcircumferential groove 26, the guide clamp 14 prevents rotation of thedriving bit 18. With the guide clamp 14 engaged with the firstcircumferential groove 26, the user is able to guide the driving bit 18toward the head of the screw and engage the driving bit 18 with the headof the screw. The guide clamp 14 prevents rotation of the driving bit 18to allow the driving bit 18 to be easily positioned in the desiredorientation.

The opening 44 defined by the closable jaw 42 can be a circular openingor a semi-circular opening. For example, the opening 44 can enclose onlya portion of the circumference of the driving bit 18, allowing the guideclamp 14 to be translated axially transverse to the longitudinal axis Ato engage the grooves 26, 28.

In addition, the closable jaw 42 of the guide clamp 14 can rotatablyhold the driving bit 18 by engaging the closable jaw 42 into the secondcircumferential groove 28. The diameter of the opening 44 is greaterthan the second outer diameter 29. As a result, the driving bit 18 isable to freely rotate about its longitudinal axis A while being held bythe guide clamp 14. Alternatively, the diameter of the opening 44 isequal to or slightly less than the second outer diameter 29, butconfigured to grip the second circumferential groove 28 lightly suchthat the driving bit 18 is able to rotate. With the guide clamp 14engaged with the second circumferential groove 28, the user is able torotate the shaft 16 and, thereby, the driving bit 18 to tighten orloosen a screw. The engagement of the guide clamp 14 with the secondcircumferential groove 28 aids the user in manipulating the driving bit18 and maintaining engagement of the driving bit 18 with the head of thescrew.

In use, the guide clamp 14 is initially engaged with the firstcircumferential groove 26 to prevent rotation of the driving bit 18, asshown in FIG. 5. After the screw engaging portion 24 of the driving bit18 is engaged with the head of the screw, the closable jaw 42 isdisengaged from the first circumferential groove 26. The closable jaw 42is then moved to a position aligned with the second circumferentialgroove 28 and then closed to engage the second circumferential groove28, as shown in FIG. 6. The user is then able to rotate the shaft 16 anddriving bit 18 to tighten the screw while at the same time maintainingthe guide clamp 14 in position to prevent the screw engaging portion 24from disengaging the head of the screw.

The guide clamp 14 can be any instrument that can engage the firstcircumferential groove 26 and the second circumferential groove 28. Forexample, the guide clamp 14 can be forceps, as shown in FIGS. 4A and 4B.In one embodiment, squeezing the arms 41 of the forceps causes theclosable jaw 42 to close and, thereby, engage the driving bit 18. Thearms 41 can then be released to open the closable jaw 42 and disengagethe driving bit 18.

FIG. 7 is an illustration of the screw driver system 10 being used tosecure an acetabular cup 48 to a patient's anatomy using one or morescrews 50. In such a use, space constraints can limit a user's abilityto manipulate a driving bit directly with their hand. This can make itdifficult to accurately engage the driving bit with the screw. Byproviding a screw driver system 10 of the screw driving bit 18 and theguide clamp 14 that are configured to cooperate in the manner describedabove, the user can easily guide the screw driving bit 18 onto a screw50 and tighten or unscrew the screw 50.

According to another aspect, a method for using the screw driving bit 18for tightening or loosening a bone screw is disclosed. The methodcomprises: tightly holding the screw driving bit with a guide clamp 14by engaging the first circumferential groove's bottom surface with theguide clamp; guiding the screw engaging portion of the screw driving bitonto the head of the bone screw; releasing the guide clamp from thefirst circumferential groove; rotatably holding the screw driving bitwith the guide clamp by engaging the second circumferential groove'sbottom surface with the guide clamp; and tightening or loosening thebone screw by turning the screw driving bit while rotatably holding thescrew driving bit with the guide clamp.

In another embodiment, as shown in FIG. 8, a screw driving bit 118 isprovided where the screw driving bit 118 has just one circumferentialgroove 128 that is a free spinning groove like the secondcircumferential groove 28 provided on the screw driving bit 18. Thus,the screw driving bit 118 is utilized in situations where there is noneed to fixedly hold the screw driving bit with the guide clamp. Theguide clamp is just used to guide the screw driving bit 118 onto a screwthen hold the screw driving bit 118 while the screw is tightened.

According to another aspect, a method for using the screw driving bit118 for tightening or loosening a bone screw is disclosed. The methodcomprises: rotatably holding the screw driving bit 118 having the singlecircumferential groove 128 with a guide clamp 14 by engaging thecircumferential groove's bottom surface with the guide clamp; guidingthe screw engaging portion of the screw driving bit onto the head of thebone screw; and tightening or loosening the bone screw by turning thescrew driving bit while rotatably holding the screw driving bit with theguide clamp.

In another embodiment, a method of installing a screw in an acetabularcup using the screw driver systems described herein is provided. Themethod includes providing a screw driver system including a screw driverand a guide clamp. The screw driver system includes a driving bit havinga first circumferential groove and a second circumferential groove. Themethod further includes engaging the guide clamp with the firstcircumferential groove such that the guide clamp restricts rotation ofthe driving bit. The method further includes engaging a screw engagingportion of the driving bit with a head of the screw. The method alsoincludes disengaging the guide clamp from the first circumferentialgroove and engaging the guide clamp with the driving bit's secondcircumferential groove such that the driving bit is able to rotate withrespect to the guide clamp. The method also includes rotating thedriving bit to install the screw.

In another embodiment, a method of removing a screw from an acetabularcup using the screw driver systems described herein is provided. Themethod includes providing a screw driver system including a screw driverand a guide clamp. The screw driver system includes a driving bit havinga first circumferential groove and a second circumferential groove. Themethod further includes engaging the guide clamp with the firstcircumferential groove such that the guide clamp restricts rotation ofthe driving bit. The method further includes engaging a screw engagingportion of the driving bit with a head of the screw. The method alsoincludes disengaging the guide clamp from the first circumferentialgroove and engaging the guide clamp with the driving bit's secondcircumferential groove such that the driving bit is able to rotate withrespect to the guide clamp. The method also includes rotating thedriving bit to remove the screw.

While the foregoing description and drawings represent preferred orexemplary embodiments of the present invention, it will be understoodthat various additions, modifications and substitutions may be madetherein without departing from the spirit and scope and range ofequivalents of the accompanying claims. In particular, it will be clearto those skilled in the art that the present invention may be embodiedin other forms, structures, arrangements, proportions, sizes, and withother elements, materials, and components, without departing from thespirit or essential characteristics thereof. In addition, numerousvariations in the methods/processes described herein may be made withoutdeparting from the spirit of the invention. One skilled in the art willfurther appreciate that the invention may be used with manymodifications of structure, arrangement, proportions, sizes, materials,and components and otherwise, used in the practice of the invention,which are particularly adapted to specific environments and operativerequirements without departing from the principles of the presentinvention. The presently disclosed embodiments are therefore to beconsidered in all respects as illustrative and not restrictive, thescope of the invention being defined by the appended claims andequivalents thereof, and not limited to the foregoing description orembodiments. Rather, the appended claims should be construed broadly, toinclude other variants and embodiments of the invention, which may bemade by those skilled in the art without departing from the scope andrange of equivalents of the invention. All patents and published patentapplications identified herein are incorporated herein by reference intheir entireties.

What is claimed is:
 1. A screw driver system comprising: a screw drivingbit comprising: a unitary body having a first end and a second end anddefining a longitudinal axis between the first end and the second end,wherein the body having an outer surface comprising a cylindricalportion between the first end and the second end; a shaft engagingportion at the first end configured to couple to the shaft; a screwengaging portion at the second end, the screw engaging portion shapedand configured to engage a head of a screw; and a first circumferentialgroove and a second circumferential groove provided on the outer surfaceof the cylindrical portion, wherein each of the circumferential grooveshaving side walls and a bottom surface, wherein the bottom surface ofthe first circumferential groove defining a first outer diameter and thebottom surface of the second circumferential groove defining a secondouter diameter, wherein the second circumferential groove is deeper thanthe first circumferential groove, whereby the second outer diameter issmaller than the first outer diameter; and a guide clamp comprising: atleast one arm; a closable jaw for holding the screw driving bit, whereinthe jaw forms an opening when closed, wherein the opening having adiameter that is larger than the second outer diameter of the screwdriving bit but smaller than the first outer diameter of the screwdriving bit, whereby the guide clamp can tightly hold the screw drivingbit by engaging the closable jaw into the first circumferential grooveand clamping the first circumferential groove's bottom surface andrestricting the screw driving bit from rotating about its longitudinalaxis; and whereby the guide clamp can rotatably hold the screw drivingbit by engaging the closable jaw into the second circumferential groovewithout clamping the second circumferential groove's bottom surface,thus allowing the screw driving bit to rotate about its longitudinalaxis while being held by the guide clamp.
 2. The screw driver system ofclaim 1, wherein the first circumferential groove and the secondcircumferential groove are fixed in an arrangement wherein they arecoaxially positioned about the longitudinal axis.
 3. The screw driversystem of claim 1, wherein the head of the screw is a socket head andthe screw engaging portion includes a male portion configured to engagethe socket head.
 4. The screw driver system of claim 1, wherein the headof the screw is a male head and the screw engaging portion includes arecess configured to receive the male head.
 5. The screw driver systemof claim 1, wherein the first circumferential groove is distal to thesecond circumferential groove.
 6. The screw driver system of claim 1,wherein each of the circumferential grooves has a rectangular crosssectional shape.
 7. A method for using a screw driving bit fortightening or loosening a bone screw, wherein the screw driving bitcomprising: a unitary body having a first end and a second end and alongitudinal axis defined between the first end and the second end,wherein the body having an outer surface comprising a cylindricalportion between the first end and the second end; a shaft engagingportion provided at the first end configured to couple to a shaft; ascrew engaging portion provided at the second end, the screw engagingportion shaped and configured to engage a head of the bone screw; and afirst circumferential groove and a second circumferential grooveprovided on the outer surface of the cylindrical portion, wherein eachof the circumferential grooves having side walls and a bottom surface,wherein the bottom surface of the first circumferential groove defininga first outer diameter and the bottom surface of the secondcircumferential groove defining a second outer diameter, wherein thesecond circumferential groove is deeper than the first circumferentialgroove, whereby the second outer diameter is smaller than the firstouter diameter, the method comprising: tightly holding the screw drivingbit with a guide clamp by engaging the first circumferential groove'sbottom surface with the guide clamp; guiding the screw engaging portionof the screw driving bit onto the head of the bone screw; releasing theguide clamp from the first circumferential groove; translating the guideclamp along the longitudinal axis to the second circumferential groove;rotatably holding the screw driving bit with the guide clamp by engagingthe second circumferential groove's bottom surface with the guide clamp;and tightening or loosening the bone screw by turning the screw drivingbit while rotatably holding the screw driving bit with the guide clamp.8. A method for using a screw driving bit for tightening or loosening abone screw, wherein the screw driving bit comprising: a unitary bodyhaving a first end and a second end and a longitudinal axis definedbetween the first end and the second end, wherein the body having anouter surface comprising a cylindrical portion between the first end andthe second end; a shaft engaging portion provided at the first endconfigured to couple to a shaft; a screw engaging portion provided atthe second end, the screw engaging portion shaped and configured toengage a head of the bone screw; and a circumferential groove providedon the outer surface of the cylindrical portion, wherein thecircumferential groove has side walls and a bottom surface, wherein thebottom surface of the circumferential groove defining an outer diameter,the method comprising: rotatably holding the screw driving bit with aguide clamp by engaging the circumferential groove's bottom surface withthe guide clamp; guiding the screw engaging portion of the screw drivingbit onto the head of the bone screw; and tightening or loosening thebone screw by turning the screw driving bit while rotatably holding thescrew driving bit with the guide clamp.